Cap insulator and material and process for manufacturing the same



L. G. LANGE Jan. 31, 1923.

$5 FOR MANUFACTURING THE SAME CAP INSULATOR AND MATERIAL AND PROCE Filed Dec. 1924 INVENTOR' law/em? Q, Lange BY 6 WflLa/m/z/m 2W g ATTORNEYS Patented Jan. 31, 1928 UNITED STATES PATENT orrlca.

LOUVERN G. LANGE, F PASSAIG, NEW JERSEY.

CAP INSULATOR AND MATERIAL AND PROCESS FOR MANUFACTURING THE SAME.

Application filed December 16, 1924. Serial No. 756,209.

In the marketing of preserves, mayonnaise, mustard, and merchandise of like character, it is customary to use glass bottles or jars equipped with metal caps, and in order that the contents of the bottle may be insulated from the metal and may be kept free from exposure to air and dirt, it has been customary to line these metal caps with composite discs of paper, these discs bein-g varnished on the side which contacts with the contents of the bottle so that the contents will not soak through the paper to the metal cap where corrosion might be set up. I

The present invention relates to improved insulating discs and material therefor, and to a process and sub-processes whereby these products are produced.

Fig. l is a diagrammatic side elevation 0 of apparatus employed in the first portion of the process of the present invention, and

Fig. 2 is a similar view of apparatus employed in the latter portion in the process of my invention.

According to the present standard practice the process of making cap insulators may be described as follows:

Starting with paper three feet wide and in a 500 ft. roll, the paper is varnished on go one side by being passed over a roller which dips into a tank of varnish and thus spreads the varnish in an even layer on one side of the paper. Papers known to the trade as kraft paper, express paper or rope paper,

and with a thickness of from four to six thousandths of an inch before being coated are suitable for this work. The varnish may be a pure quick drying oil varnish and may be applied of a thickness of from one thousandth to two thousandths of an inch. After being passed over the varnishing roll the continuous sheet is suspended on a looper and dried with heat. It requires about one half hour to dry the paper while it is moving in looped form through the drier. When varnish is applied to one side of a paper sheet in this manner it soaks through the sheet to the opposite side. Uncalendered paper is ordinarily used.

After the drying above described the paper is again wound up in a roll and is ready for storage, or for distribution to the consumer.

A thin varnished sheet as above described is not thick enough for successful use as a cap insulator. It must be backed up with a thicker layer of porous paper or cardboard for otherwise the insulator could not be relied on to make a tight joint between the metal cap and the glass container to which the cap is attached, usually by screw threads.

Inasmuch as the varnish has soaked through to the back surface of the paper the attachment of such a thick and porous sheet of paper or cardboard presents some difficulties. Machines have been devised for doing this work, although these machines are somewhat complex and expensive, costing in the neighborhood of $2000.00.

In such machines varnished paper in the form of a roll is unwound and passed over a roller which dips in an adhesive in a tank 7 where it is kept hot by a gas flame. Hot gum must be used becauseof the presence of varnish in and 'on the paper sheet, Suitable gums may be made from rosin, glycerine and non-drying oils which are now available at a cost of about 18 per pound.

The next step in the old process consists in passing the gummed sheet through a pair ofpress rolls where the hot gummed side is pressed into intimate contact with a sheet of pulp board or news boardunwound from a roll. This porous backing sheet may have a s5 thickness of from twenty five thousandths to fifty thousandths of an inch. When the continuous sheet comes from rollers it is cut into rectangular panels or sheets, say three feet square. These panels are then stacked and allowed to dry for about two days. Discs cannot be punched from them 1 immediately after they have been formed because the adhesive is still plastic nou h to gum up any cutting dies that might e used.

After drying or aging for about two days these flat panels or sheets, according to standard practice, are placed on a wooden chopping block in a crude sort of punch press and a hollow die is moved about b hand under the platen of the press to punch discs from the paper panels or sheets. These discs accumulate in the hollow punch from which they ultimately are removed and placed by hand one at a time in the caps where they are to be used, the pulp board face being placed toward the metal.

The foregoing standard practice presents the disadvantages of requiring a relatively expensive machine, a larger storage capacity at the plant, an expensive adhesive, and considerable skill and experience in the manipu' lation of hot gum. Even under the best of conditions, blisters will develop in the composite sheet, and finished cap insulators punched therefrom will split apart during subsequent handling and use.

All of the foregoing disadvantages of the old practice are overcome by the process hereinafter described and claimed in detail.

Referring to Fig. 1 of the drawings, the reference numeral 1 designates a roll of kraftpaper, express paper or rope paper of any suitable thickness, say .004 to .006. The paper is fed over a roll 2 dipping into a tank 3 and adapted to apply a layer 4 of water soluble gum to one surface of the paper. The gum may be maintained in litl uid condition by asuitable burner 5. T 1e continuous sheet is dried in a hot box (5 and is then in condition for the application of the varnish to the opposite face. The gum or adhesive may be of the dextrine ty e, or may be an animal glue or may be a h glue.

A layer of quick drying oil varnish may then be applied to the uncoated surface of the paper sheet. The paper passing from the dryer 6 may pass over suitable idler rolls to reverse it and place the gummed surface uppermost. It is then passed over a roll 21 which dips into a tank 22 containing the varnish. The varnish may be maintained at any desired temperature by means of a burner 23. After a coating 24: of varnish has been applied to the paper, it may be delivered through a festooned dryer 25 looping over roller 26 arranged in the top and bottom of a dryer. The paper, coated on both surfaces, may be then wound on a roll 27.

This process of varnishing the paper follows i the standard practice except that the presence of the water soluble gum on the reverse side of the paper sheet prevents the varnish irom soaking through it to the reversed sur ace.

The layer of varnish so applied can advantageously be from .001 to .002" thick.

' Paper assembled in 500 ft. rolls and coated on one side with a good oil varnish and coated on the other side with a water soluble gum can be conveniently transported and is, in itself, a marketable commodity, suitable for convenient shipment to the bottle cap maker or consumer.

The varnished surface may be waxed by known processes to meet special demands of the trade, paraffin, or any good bread wrapper wax, being used for that purpose. Similarly, when a highly waterproofed cap insulator is desired, the paper may be coated with nitro cellulose and gums such as commercial dammar before the varnish is applied, and the layer of varnish can then 8 waxed as before.

The next step in my complete process is illustrated diagran'imatically in the drawings and consists in unwinding the gummed varnish sheet from roller 8 and passing it over a roller 9, dipping in water 10. While the gummed sheet is still wet with water it is brought into contact with a sheet of pulp board or news board twenty-five to fifty thousandths of an inch thick unwound from a roll 11. The two sheets are passed between rolls 12 and 13 and thus are brought into intimate contact. The composite sheet thus formed, instead of being cut into panels and put in storage for many hours, is immediately passed to a punch press of the battery' type comprising a row of plungers l4 and dies 15, whereby the desired discs can be cut simultaneously across the entire width of the composite sheet. The fact that the water soluble gum has been used as the adhesive instead of a hot rosin gum permits this prompt punching of the discs. ln commercial practice, it is convenient to deliver the discs through dies 15 directly into bottle caps 16 carried on a transverse conveyor 17. Much hand operation is thus eliminated.

In the practice above described the machine is of simple and inexpensive construction, the adhesive is cheap in cost and easy to manipulate to insure a permanent close adhesion between the two sheets, and there is no need for elaborate storage space in which to age the adhering materials. But equally important, there is a prompt and orderly delivery of the finished discs, right side up in the metal caps in which they are to remain withoutthe intervention of any substantial amount of manual handling.

I claim:

1. In a process of manufacturing cap' insulators, the steps which consist in coating 1 one side of a sheet of tough aper with a. Water soluble gum, then drying the gum, then varnishing the other side of said sheet and drying the varnish, subsequently wetting the gummed surface with water and bringing into contact with the wet surface a porous padding sheet, rolling said sheets together and immediately punching therefrom discs suitable for use as cap insulators, substantially as described.

2. The method which comprises coating one surface of a sheet of tough dense paper with a water soluble gum, then drying the sheet and then coating the other side of said sheet with varnish and drying and waxing the varnish and rolling said sheet into a the composite sheet so formed discs suitable roll adapted for convenient storage and shipfor use as cap insulators and simultaneously ment, subsequently unrollin said gummed deliverin said discs directly into the caps 0 and varnished sheet and wetting the gummed wherein t ey are to be used, substantially as 5 side with water, pressing a porous aper described. a

sheet into contact with the wet gumm sur- In testimony whereof I aflix my nature. face as the paper is unrolled, punching from LOUVERN G GE. 

